magnetic field

I find it very interesting that scientists have discovered they can determine the strength of earths magnetic field at various times throughout history by analyzing old pottery. When fired the iron molecules or flakes or whatever they may be align a certain way and in a sense are magnetized. For those concerned about climate change (which I believe is solely related to sunspot activity) I would say that if we lose our magnetic shield we will be soaked with solar radiation and like a fool in the rain without an umbrella soon get very ill and pass on. I believe that mars lost its magnetic field and that is what happened to any life or water that existed there. They say our field is weakening but I am not sure I believe it...as long as the earth is filled with a bunch of molten iron sloshing and spinning about we should be okay. The polar ice caps have grown 30 % this year as we are at our 50 year low now in suspots. My view on global warming is not loved by many people but for some reason no one cares about the magnetic poles.